524 THE VOYAGE OF H.M.S. CHALLENGER.] 



little bent. Whorls 8 in all ; they are cylindrical and convex, and become increasingly 

 long and narrow ; the last has a short rounded base. Suture openly and slightly impressed. 

 Mouth small and round. Outer lip sharp but strong, very regularly arched, and project- 

 ing to the side. Inner lip : it runs without an angle into the outer lip, across the body 

 it is strong and slightly disunited, the pillar scarcely exists, and the projecting lip-edge 

 curves round to the basal lip. H. 0-049 in. B. 0-015. Mouth, height 0-01, breadth 0'01. 



I do not know whether this wonderful little species can fairly come into the genus Mucronalia 

 of Adams, but I really do not know where else to put it, and it has some features of the group ; the 

 tip is abnormal, though certainly not stiliform. 



9. Stilifer, Broderip, 1832. 

 ' Species. 



1. Stilifer brychius, Wats. 2. Stilifer crof aphis, n. sp. 



1. Stilifer brychius, 1 Watson (PI. XXXVII. fig. 9). 



Stilifer brychius, Watson, Prelim. Report, pt. 17, Journ. Linn. Soc. Lond., voL svii. p. 130. 

 Station 325. March 2, 1876. Lat. 36° 44' S., long. 46° 16' W. South Atlantic. 

 2650 fathoms. Blue mud. Bottom temperature 32°7 Fabr. 



Sliell. — In form somewhat like Littorina rudis, Maton, of the var. tenebrosa; but 

 shorter in base, with a tumid and larger penultimate whorl, very thin, hyaline and glossy, 

 with faint spirals and lines of growth : the generic pillared tip is small. Sculpture : 

 Longitudinals — the whole surface is closely scored with slight obsolete and very fine 

 threadlets, which are the lines of growth. Spirals — of these there are many, somewhat 

 broadish but very obsolete ; they are unequal, and one forms a feeble angulation consider- 

 ably above the middle of the whorl. Colour pure glassy white, thin, and perfectly 

 transparent. Apex : the style is quite straight, well defined, short and small, and consists 

 of two whorls. Spire conical and rather high. Whorls 6, of rapid but regular increase, 

 obliquely shouldered above from the suture to the very slight angulation, rounded below. 

 Suture strong, linearly impressed, submarginated below. Mouth roundly pear-shaped, 

 being shortly pointed above, large. Outer lip leaves the body-whorl at a right angle ; 

 it is slightly patulous, and is well arched throughout. Inner lip very oblique, scarcely 

 convex above ; it is very concave at the junction of the body and the pillar, which last is 

 flattened and very slightly twisted and runs out to a very sharp edge. H. 0*5 in. 

 B. 0-39. Penultimate whorl, height 0'14. Mouth, height 0-33, breadth 0'3. 



The solitary specimen got of this species is preserved in spirit ; but I failed to extract the animal. 

 The shell is so delicate that no force can be used. The colour is that pale uniform buff which is so 

 common to deep-sea Mollusca. The mantle lines the shell all round. From the middle of this pro- 



1 j3c!>%io;, from the depths. 



